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Showing posts with the label ORA-01722

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Top Questions People Ask About Pandas, NumPy, Matplotlib & Scikit-learn — Answered!

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 Whether you're a beginner or brushing up on your skills, these are the real-world questions Python learners ask most about key libraries in data science. Let’s dive in! 🐍 🐼 Pandas: Data Manipulation Made Easy 1. How do I handle missing data in a DataFrame? df.fillna( 0 ) # Replace NaNs with 0 df.dropna() # Remove rows with NaNs df.isna(). sum () # Count missing values per column 2. How can I merge or join two DataFrames? pd.merge(df1, df2, on= 'id' , how= 'inner' ) # inner, left, right, outer 3. What is the difference between loc[] and iloc[] ? loc[] uses labels (e.g., column names) iloc[] uses integer positions df.loc[ 0 , 'name' ] # label-based df.iloc[ 0 , 1 ] # index-based 4. How do I group data and perform aggregation? df.groupby( 'category' )[ 'sales' ]. sum () 5. How can I convert a column to datetime format? df[ 'date' ] = pd.to_datetime(df[ 'date' ]) ...
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How to Resolve ORA-01722 Invalid Number Error in Oracle SQL Developer

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When working with Oracle SQL Developer, you may come across an error message that reads "ORA-01722: invalid number". This error can be frustrating and difficult to understand, especially if you're new to SQL. In this post, I will explain the cause of this error and provide a solution to resolve it. Cause of the Error - ORA-01722 Let's consider an example where we have two tables named "my_hr" and "my_dept". The "my_hr" table contains three columns - "name", "pay_id", and "user_id", while the "my_dept" table contains two columns - "name" and "user_id". CREATE TABLE my_hr ( name CHAR(20), pay_id NUMBER, user_id CHAR(6) ); CREATE TABLE my_dept ( name CHAR(20), user_id CHAR(6) ); Now, let's insert some sample data into these tables: INSERT INTO my_hr VALUES ('Srini', 567, '123456'); INSERT INTO my_dept VALUES ('Srini', '123456'); If we try to execu...
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